For an existing SIM card connector, in a case in which a battery is not pulled out, when a user takes a SIM card out of or puts a SIM card into the SIM card connector that is in a power-on state, a card burn out phenomenon is likely to occur. A reason is that the SIM card connector is still in the power-on state when the user performs a card insertion or removing action, and in this case, hot swap causes a momentary electric arc to be generated between a gold-plated area of the SIM card and signal spring. Consequently, a contact area is burned out, and the card cannot be read when the user uses a mobile phone.